Module 17: Overlapping Sets

Question 1

Finding Total Number of Unique Elements for 2 overlapping sets: 2 important formulas

Answer 1

1) Number of A only + Number of B only + Both + Neither = Total (i.e. adding up the 4 top left squares in the matrix will give the total)
2) Total A + Total B - Both + Neither = Total

Question 2

Number of members in set A OR B, not both

Answer 2

Total A + Total B - Both

Question 3

Solving problems with 3 overlapping sets

Answer 3

Draw a three circle Venn diagram, one circle per item. Use overlaps as needed. DON’T forget to include a “nether region” where none of the items apply.

Question 4

3 overlapping sets: Total Number of Unique Items (2 formulas)

Answer 4

1) Individual parts
# A only + # B only + # C only + A&B Only + A&C Only + B&C Only + # in Triple Overlaps + # in Neither

2) Accounting for overlaps

Total A + Total B + Total C - # in Groups of 2 - 2(# in Groups of 3) + No Group